The Solid POP3 Server is an implementation of a Post Office Protocol version 3 server that has flexibility as its main goal. The server is easily configurable and has support for few features such as: - APOP authentication scheme - virtual hosting - maildir and mailbox handling - bulletins - expiration of messages Each user can specify his maildrop (its position and type). The format used in specification of maildrop's position should handle almost all widely-used system configurations. The server also seems to be fast, however no tests have been performed, so it's rather relative feeling. The design used is very similar to the design of Solar Designer's POPA3D server. This solution let's minimalize size of code working with root privileges. The code was also heavily checked for buffer overflow leaks and file races. None have been found as for now. All operations on files are done with user privileges. There is no SUID APOP secrets database management program (as in QPOP). Each user can specify his secret in his own home directory. WWW: http://solidpop3d.pld.org.pl/